Modern society is heavily reliant upon many different kinds of audio/video and data telecommunications services affecting all aspects of daily life. Television is one of the most popular sources of information and entertainment. Other sources of information and entertainment include computer networks such as the Internet, which today offers services such as interactive shopping, banking, gaming, venues for discussion and social intercourse and many other products and services, home video games, video/DVD movie rentals, radio and television broadcasts and the like. These types of services provide a virtually unlimited variety of information and entertainment to practically every corner of the world.
However, these services have evolved independently over many decades and as such are provided in different formats and through disparate channels of distribution. For example, television signals can be received by off-air antenna, cable redistribution networks (CATV) and satellite broadcasts, but access to each signal source is independent of the others and requires specialized equipment and/or service providers. A television set can be equipped to receive signals from all of these sources, but only one at a time so some form of switching equipment at the receiving end is required to change the television signal source. Further, each of these signals itself comprises many channels, which complicates attempts to pool the services into a single integrated system. The Internet is accessible by modem over CATV or telephone wires, but is typically connected to a computer which is a completely separate viewing system.
Prior to the invention there has never been a system available for integrating these types of services, which would allow a user to instantaneously access any channel provided by any telecommunications or broadcast service using a single system. Moreover, prior to the invention there has not been an inexpensive system available which is interactive, simple to use and delivers any desired telecommunications and broadcast service over a single network of twisted pair telephone wires.
A new technology known as Digital Subscriber Line (DSL) is now available which carries high-bandwidth data to subscribers over PSTN telephone lines using a form of fixed frequency Direct Multitone (DMT). Where the subscriber is located in proximity to a telephone company which offers DSL service, data rates of up to 7 Mb/s are available, which permits the continuous transmission of video (including motion video) and audio signals without interfering with telephony (voice) transmissions.
In conventional analog telephony the data rate is limited by filters which convert digital data streams to analog form suitable for PSTN telephone transmission cables, which is very bandwidth intensive. In DSL, digital data is transmitted without conversion to analog, which allows for a much wider transmission bandwidth in a signal that can be separated from the analog voice signal. However, in order to accomplish this over existing PSTN wiring, all existing digital-to-analog filters must be removed, which is a very expensive process, which increases as the distance from the telephone company facility increases, and results in a high cost to DSL subscribers. Moreover, outdoor PSTN cable is subject to degradation, and any signal carried on outdoor wiring is vulnerable to ambient em interference and attenuation due to multiple taps and other connections. These factors combine to limit the usefulness of fixed frequency DMT.
It would accordingly be advantageous to provide a system for integrating broadcast and telecommunications signals from a variety of sources, which can utilize conventional twisted-pair telephone wiring within a subscriber's premises and does not rely upon transmission to the premises via outdoor PSTN cables utilizing dynamic frequency allocation (DFA). It would further be advantageous to provide such a system which permits interactive signal selection of virtually any type of broadcast or telecommunications signal by a user, and which maximizes definition and minimizes interference by adaptively allocating bandwidth to signals based on the nature of the signal and its data content, amongst other factors.